This section provides background information related to the present invention, which is not necessarily prior art.
In many different vehicle applications, vehicle panels are utilized to form various parts of a vehicle. Such vehicle panels may include door module carriers, trim pieces, firewalls, sheet metal panels, frame components, dash mats, headliners, tailgate panels, floor panels, insulating mats, and dampening mats. Often such vehicle panels have one or more holes that facilitate installation of the vehicle panel during assembly of the vehicle. For example, such holes may receive fasteners that attach the vehicle panel to a vehicle component or may provide tool access to otherwise obstructed locations. In some instances, these holes are left open in areas of the vehicle that are hidden from view or are designed to be left open to the outside environment. However, many times it is desirable to fill these holes after installation of the vehicle panel to improve the overall appearance of the vehicle or to prevent the incursion of air, dust, water, and noise through the hole.
One solution for filling holes in vehicle panels is to install a push plug in each hole during the assembly process. Some vehicles have hundreds of push plugs serving this purpose. To facilitate the assembly process and to ensure that the push plugs are not lost, the push plugs may be provided with a tether that permanently attaches the push plugs to the vehicle panel at locations adjacent the holes. Once the vehicle panel has been installed and the hole is no longer need, an assembly line operator grabs a push plug, aligns the push plug with the hole, and presses the push plug into the hole. A common problem in such an assembly process is that the push plugs are improperly installed on occasion where the push plug is not fully seated in the hole. At some point during the assembly process, the improperly installed push plug becomes dislodged from the hole allowing the incursion of air, dust, water, and noise through the hole.
An assembled vehicle with an improperly installed push plug is difficult to identify because the tether retains the improperly push plug on the vehicle panel even though it is no longer engaged in the hole. Current methods for identifying such quality problems include water tests that involve submersing an assembled vehicle or a portion thereof in a water bath. The vehicle is then inspected for leaks. Such testing is time intensive and expensive so only a few vehicles in every assembly run are subjected to water tests. The frequency of such tests makes it difficult to identify intermittent quality problems such as improperly installed push plugs. Additionally, when water testing does reveal an improperly installed push plug, much of the vehicle has to be disassembled to find the root cause of the leak and to re-install the push plug. What is needed is a way to reliably identify improperly installed push plugs early on in the assembly process.